Module: ShopifyCLI::MethodObject

Included in:
Extension::Forms::Questions::AskApp, Extension::Forms::Questions::AskName, Extension::Forms::Questions::AskRegistration, Extension::Forms::Questions::AskTemplate, Extension::Forms::Questions::AskType, Extension::Tasks::ChooseNextAvailablePort, Extension::Tasks::ConfigureFeatures, Extension::Tasks::ConfigureOptions, Extension::Tasks::ExecuteCommands::OutdatedExtensionDetection::OutdatedCheck, Extension::Tasks::FetchSpecifications, Extension::Tasks::FindNpmPackages, ResolveConstant, TransformDataStructure
Defined in:
lib/shopify_cli/method_object.rb

Overview

The ‘MethodObject` mixin can be included in any class that implements `call` to ensure that

  • ‘call` will always return a `ShopifyCLI::Result` by prepending a module that takes care of the result wrapping and

  • a ‘to_proc` method that allows instances of this class to be passed as a block.

For convenience, this mixin also adds the corresponding class methods: ‘call` and `to_proc`. Method and result objects pair nicely as they greatly simplify the creation of complex processing chains:

class Serialize
  include MethodObject

  def call(attrs)
    attrs.to_json
  end
end

class Deserialize
  include MethodObject

  def call(json)
    JSON.parse(json)
  end
end

Serialize
  .call(firstname: "John", lastname: "Doe")
  .then(&Deserialize)
  .map { |attrs| OpenStruct.new(attrs) }
  .unwrap(nil)

While this example is contrived, it still illustrates some key advantages of this programming paradigm:

  • chaining operations is as simple as repeatedly calling ‘then` or `map`,

  • method objects don’t have to be manually instantiated but can be constructed using the ‘&` operator,

  • error handling is deferred until the result is unwrapped.

Please see the section for ‘ShopifyCLI::Result`, `ShopifyCLI::Result::Success`, and `ShopifyCLI::Result::Failure` for more information on the API of result objects.

Defined Under Namespace

Modules: AutoCreateResultObject, ClassMethods

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.included(method_object_implementation) ⇒ Object

is invoked when this mixin is included into a class. This results in

  • including ‘SmartProperties`,

  • prepending the result wrapping mechanism, and

  • adding the class methods ‘.call` and `.to_proc`.



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# File 'lib/shopify_cli/method_object.rb', line 109

def self.included(method_object_implementation)
  method_object_implementation.prepend(AutoCreateResultObject)
  method_object_implementation.include(SmartProperties)
  method_object_implementation.extend(ClassMethods)
end

Instance Method Details

#to_proc ⇒ Object

returns a proc that invokes ‘call` with all arguments it receives when called itself.



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# File 'lib/shopify_cli/method_object.rb', line 119

def to_proc
  method(:call).to_proc
end